A bullet swap is an interest rate swap whose notional principal stays fixed for the entire term of the contract and settles in a single large payment at maturity. The shape mirrors a bullet bond or balloon-payment loan, which is exactly why borrowers and investors use it: the swap’s cash flows can be lined up against a debt obligation that repays its full principal on one specific date.
How the Structure Works
An interest rate swap has two sides, called legs. One leg pays a fixed rate locked in when the contract is executed. The other pays a floating rate tied to a market benchmark. For U.S. dollar swaps, that benchmark is the Secured Overnight Financing Rate (SOFR), which fully replaced LIBOR after its final USD settings ceased on June 30, 2023.1Federal Reserve Bank of New York. Transition from LIBOR Swap products reference an average of SOFR rather than a single day’s reading when they calculate floating payments.2Federal Reserve Bank of New York. An Updated User’s Guide to SOFR
The notional principal is the dollar figure both parties use to size their interest payments. In a standard single-currency interest rate swap, neither party actually delivers the notional. It sits on paper as a reference number. A bullet swap follows that same convention during the life of the contract, but the notional factors into the final settlement at maturity, producing one large terminal cash flow that lines up with the borrower’s principal repayment on a bullet bond or loan.
Interest is exchanged on a regular schedule. Quarterly, semi-annual, and annual frequencies are all common.3Commodity Futures Trading Commission. Tradeweb Swap Specifications On each payment date, only the net difference between the fixed and floating amounts moves. If the fixed rate is 4% and SOFR averages 3.5% for the period, the fixed-rate payer owes the difference to the floating-rate payer. The notional itself is untouched until maturity.
A Worked Example
Say a company issues a five-year, $100 million bond that pays a floating rate (SOFR plus a spread) and repays the entire principal at maturity. The treasurer is worried SOFR will rise. To lock in predictable costs, the company enters a bullet swap paying a fixed 4.25% and receiving SOFR.
Each quarter, interest is calculated on the $100 million notional. If SOFR averages 3.80%, the company owes the roughly 0.45% annualized difference to the counterparty. If SOFR jumps to 5.00%, the counterparty owes the company the 0.75% difference. Either way, the company’s effective borrowing cost stays near 4.25%, because the floating payments it receives on the swap offset the floating coupon it owes on the bond.
At the end of year five, the bond matures and the company repays the full $100 million to its bondholders. The swap’s final settlement accounts for this terminal cash flow. The swap’s cash flows have matched the bond’s throughout, which is the whole point.
How a Bullet Swap Differs From Other Swaps
Against a Plain Vanilla Interest Rate Swap
A plain vanilla swap also holds a constant notional and exchanges net interest periodically. The difference is purpose and terminal structure. A vanilla swap converts floating exposure to fixed (or the reverse) on an ongoing basis, and the notional never enters settlement because neither party has a principal obligation tied to the deal. A bullet swap adds the terminal dimension. It’s built for a hedger facing a large, one-time principal payment at the end of the contract. During the interim periods, the two structures often look identical. The difference emerges at maturity.
Against an Amortizing Swap
An amortizing swap is the structural opposite. Its notional decreases over time, tracking a loan where the borrower pays down principal on a schedule. A standard residential mortgage works this way: each payment chips away at the balance. A bullet swap keeps the notional at its full original amount from day one to the last day. Interest payments stay large the entire time, and the counterparties carry more aggregate rate exposure than they would under an amortizing structure. Exiting early is also more expensive, since the remaining notional is always the full amount.
Risks Specific to the Bullet Structure
- Concentrated counterparty exposure. The full notional is in play at maturity, so the party owed the terminal payment faces its peak credit exposure at the very end. A default near maturity produces the maximum loss. An amortizing swap does the opposite, shrinking exposure over time.
- Higher interest rate sensitivity. Every basis point of rate movement applies to the full principal the entire term. The bullet structure carries the full weight throughout.
- Refinancing risk. If the underlying bullet bond or loan can’t be refinanced at maturity, the hedger may face a mismatch between the swap’s remaining obligations and its actual funding.
- Liquidity risk. Bullet swaps are less standardized than plain vanilla swaps, and exiting a position before maturity can be difficult and costly.
Pricing at Inception
When a bullet swap is executed, the fixed rate is set so the present value of the fixed leg equals the present value of the floating leg. The swap is worth zero to both parties at that moment. Neither side pays the other to enter.
The primary input is the yield curve, which provides a discount factor for every future payment date. For the floating leg, the model uses a forward curve derived from the current SOFR yield curve; forward rates represent the market’s implied expectation for SOFR in each future period. Each expected floating payment is discounted back to present value. The fixed rate that makes the two legs’ present values equal is the answer, and it works out to a weighted average of the forward rates adjusted for the time value of money.
The large terminal cash flow shifts the swap’s sensitivity toward the long end of the yield curve. Because the biggest cash flow sits at the final maturity date, changes in long-term rates move the swap’s market value more than they would for a swap with cash flows spread evenly. Duration is higher, and small moves in long-term rates produce larger changes in mark-to-market value.
Early Termination and Breakage Costs
Walking away from a bullet swap before maturity is not free. The breakage cost depends on how much rates have moved since execution.
The basic calculation compares the fixed rate on the original swap to the current market rate for a replacement swap covering the remaining term. If you locked in 4.25% three years ago on a five-year deal and a two-year replacement swap now costs 3.50%, you’re holding a contract that’s more expensive than the current market. The breakage cost is roughly the present value of the 0.75% difference applied to the full notional for the remaining two years.
This is where the bullet structure bites. Because the notional never decreases, the breakage calculation always uses the full original amount. An amortizing swap would apply the same rate difference to a shrinking balance and produce a smaller cost. On a $100 million bullet swap with two years remaining and a 75-basis-point rate difference, the approximate breakage cost lands around $1.5 million before dealer adjustments. The actual number differs slightly because each remaining cash flow is discounted individually, and dealers typically add a spread for funding costs and bid-ask.
The math can run the other way. If rates have moved so that the replacement swap is more expensive than your original fixed rate, your swap has positive market value and the counterparty owes you a payment to terminate.
Clearing, Margin, and Documentation
Bullet swaps sit inside the regulatory framework the Dodd-Frank Act built for the U.S. swaps market.
Central Clearing
Under the Commodity Exchange Act, entering into a swap required to be cleared without submitting it to a registered derivatives clearing organization is unlawful.4Office of the Law Revision Counsel. 7 US Code 2 – Jurisdiction of Commission; Liability of Principal for Act of Agent The CFTC specifies which swap classes fall under the mandate. For U.S. dollar interest rate swaps referencing SOFR, the clearing requirement covers overnight index swaps with terms from seven days to 50 years.5eCFR. 17 CFR 50.4 – Classes of Swaps Required to Be Cleared The CFTC added SOFR-referenced swaps to these categories as part of the post-LIBOR transition.6Federal Register. Clearing Requirement Determination Under Section 2(h) of the Commodity Exchange Act for Interest Rate Swaps Central clearing places a clearinghouse between the two counterparties, which cuts the risk that one side’s default sinks the other. That matters more for bullet swaps because of the concentrated terminal exposure.
Margin on Uncleared Swaps
When a bullet swap is not centrally cleared, either because it falls outside the mandated categories or qualifies for an exemption, CFTC rules require the counterparties to post margin. The framework includes both initial margin and variation margin, with provisions such as a minimum transfer amount of up to $50,000 per separately managed account.7Commodity Futures Trading Commission. CFTC Unanimously Approves Final Rules Related to Margin Requirements for Uncleared Swaps Variation margin moves regularly to reflect changes in the swap’s market value; initial margin buffers against potential future exposure on default.
Documentation
Nearly all over-the-counter swap transactions, bullet swaps included, are governed by the ISDA Master Agreement published by the International Swaps and Derivatives Association. The Master Agreement sets the legal framework between two counterparties, covering default events, termination procedures, netting, and governing law. All individual transactions between the same two parties operate under one umbrella agreement. Each specific bullet swap is captured in a Confirmation that references the Master Agreement and sets out the deal’s terms: notional amount, fixed rate, floating index, payment dates, maturity date, and day-count conventions. A Credit Support Annex attached to the Master Agreement governs collateral: what’s acceptable and when it must be posted or returned.
Where Bullet Swaps Get Used
The most natural use is hedging a bullet bond. An issuer that pays a floating-rate coupon on a bond repaying its full face amount at maturity can enter a swap paying fixed and receiving floating. The periodic exchanges offset the bond’s floating coupon, and the terminal settlement aligns with the bond’s principal repayment. The result behaves like a fixed-rate bond without having to issue one.
Banks use bullet swaps in asset-liability management. A bank holding a ten-year fixed-rate bond funded by shorter-term floating-rate deposits faces a rate mismatch. A bullet swap lets the bank receive floating to match its funding costs while paying fixed to match the bond’s income, with the terminal payment aligned to the bond’s maturity. That smooths the duration gap between assets and liabilities.
Corporate treasurers also use bullet swaps when a large capital expenditure or debt repayment is coming on a specific future date. Locking in the cost of funding that obligation removes the risk that rates rise between now and then. The swap doesn’t change the underlying debt. It transforms the interest rate profile into something predictable, which makes budgeting easier.